Hi, I have a 1977 Coachmen camper based on a long wheelbase Econoline cab/chassis with 85,000 miles. It has the 460/C6.
We just came back from a 200 mile trip without incident. However, after letting the camper sit for about an hour, I was backing it out of the driveway and it seemed like something was dragging. The camper was shaking/vibrating. The shaking is the same in forward and reverse.
I went underneath and nothing looked out of place. There was no movement of the U-joints. The front driveshaft was pretty warm, as was the hanger bearing. Does this sound like a hanger bearing has gone out? I welcome any opinions.

 

sounds like one of the u-joints froze(seized). You need to get a look while truck is slowly rolled